In recent years, a large number of electric vehicles running with electric power from storage batteries, such as HEVs (Hybrid Electric Vehicles), PEVs (Plug-in Electric Vehicles), and EVs (Electric Vehicles), have been utilized. Examples of the storage batteries mentioned herein include a lithium ion secondary battery and a nickel hydrogen secondary battery.
Electricity storage systems for supplementing electric power supply using storage batteries have been put in practical use at, for example, houses, buildings, or factories. In such electricity storage systems, storage batteries are charged with surplus generated electric power or low cost midnight electric power, while the storage batteries are used to supply electric power to electric appliances when the amount of electric power generation decreases, or during a time period when the cost of a commercial power source is high, or when electric power is in shortage.
Moreover, as an example of the related art of the present invention, Patent Literature 1 discloses a power supply service system that manages the use state of the battery of a car and the customers and enables smooth charging and replacing of the battery.